“Other” folder is too big

Question

My "Other" folder in my mac taking every free MB it has. Note that I tried to find where it coming from but I just can't figure it out. It's 418GB in size and I have nothing on my machine that takes up so much room.

macOS Catalina v10.15.4

Filesystem      Size   Used  Avail Capacity iused      ifree %iused  Mounted on
/dev/disk1s5   466Gi   10Gi  8.3Mi   100%  487565 4881965315    0%   /
devfs          334Ki  334Ki    0Bi   100%    1156          0  100%   /dev
/dev/disk1s1   466Gi  452Gi  8.3Mi   100% 2187628 4880265252    0%   /System/Volumes/Data
/dev/disk1s4   466Gi  3.0Gi  8.3Mi   100%       3 4882452877    0%   /private/var/vm
map auto_home    0Bi    0Bi    0Bi   100%       0          0  100%   /System/Volumes/Data/home
/dev/disk1s3   466Gi  504Mi  8.3Mi    99%      40 4882452840    0%   /Volumes/Recovery

after running: sudo du -hxd1 /System/Volumes/Data

 45G    /System/Volumes/Data/Users
 28G    /System/Volumes/Data/Applications
873M    /System/Volumes/Data/opt
  0B    /System/Volumes/Data/Volumes
  0B    /System/Volumes/Data/.TemporaryItems
  0B    /System/Volumes/Data/cores
449G    /System/Volumes/Data

running sudo du -hxd1 /System/Volumes/Data :

total 2
drwxrwxr-x+ 56 root  admin  1792 Apr 20 15:52 Applications
drwxr-xr-x  70 root  wheel  2240 Dec 16 09:07 Library
drwxr-xr-x@  3 root  wheel    96 Aug 25  2019 System
drwxr-xr-x   7 root  admin   224 Sep 29  2019 Users
drwxr-xr-x   3 root  wheel    96 Apr 20 23:08 Volumes
lrwxr-xr-x   1 root  wheel   103 Apr 18  2018 com.oracle.java.Helper-Tool.plist -> /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Resources/com.oracle.java.Helper-Tool.plist
lrwxr-xr-x   1 root  wheel   104 Apr 18  2018 com.oracle.java.Java-Updater.plist -> /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Resources/com.oracle.java.Java-Updater.plist
drwxr-xr-x   2 root  wheel    64 Aug 25  2019 cores
dr-xr-xr-x   2 root  wheel     1 Apr 20 23:13 home
drwxr-xr-x   2 root  wheel    64 Aug 25  2019 mnt
drwxr-xr-x   6 root  wheel   192 Oct 11  2019 opt
drwxr-xr-x   6 root  wheel   192 Jun 30  2020 private
drwxr-xr-x   2 root  wheel    64 Aug 25  2019 sw
drwxr-xr-x   5 root  wheel   160 Sep 29  2019 usr

Answer 1

I tried several methods from the comments to solve this problem

As shown above, almost the entire hard disk is occupied by "Other". Since the operating system could sometimes get confused by the multitude of tasks, a restart could possibly solve the problem. (Enter in the terminal sudo reboot)

Since "other" can be anything, except

Books
Documents
Xcode Build caches of a project
iCloud Drive
iOS files
Mails
Programs
Other users
System

It is best to work at the root level to see what exactly is being used in conspicuous high disk space. We are examining the data partition.

$ sudo du -hxd1 /System/Volumes/Data
  0B    /System/Volumes/Data/sw
1,0K    /System/Volumes/Data/home
979M    /System/Volumes/Data/usr
271M    /System/Volumes/Data/boot
 15G    /System/Volumes/Data/Library
3,1G    /System/Volumes/Data/System
  0B    /System/Volumes/Data/mnt
 23M    /System/Volumes/Data/.fseventsd
400G    /System/Volumes/Data/private
 30G    /System/Volumes/Data/Users
 50G    /System/Volumes/Data/Applications
  0B    /System/Volumes/Data/opt
5,3M    /System/Volumes/Data/.PreviousSystemInformation
  0B    /System/Volumes/Data/Volumes
  0B    /System/Volumes/Data/cores

In my case, the /private/var directory pulls a lot. Again, I can examine the output further.

$ sudo du -hxd1 /System/Volumes/Data
  0B    /System/Volumes/Data/private/var/yp
8,0K    /System/Volumes/Data/private/var/networkd
  0B    /System/Volumes/Data/private/var/install
  0B    /System/Volumes/Data/private/var/empty
  0B    /System/Volumes/Data/private/var/ma
  0B    /System/Volumes/Data/private/var/mail
 59M    /System/Volumes/Data/private/var/spool
  0B    /System/Volumes/Data/private/var/jabberd
 24K    /System/Volumes/Data/private/var/MobileSoftwareUpdate
1,0M    /System/Volumes/Data/private/var/vm
4,0K    /System/Volumes/Data/private/var/msgs
4,0M    /System/Volumes/Data/private/var/logs
 11M    /System/Volumes/Data/private/var/audit
104M    /System/Volumes/Data/private/var/root
  0B    /System/Volumes/Data/private/var/lib
400G    /System/Volumes/Data/private/var/db
  0B    /System/Volumes/Data/private/var/at
 57M    /System/Volumes/Data/private/var/log
1,8G    /System/Volumes/Data/private/var/folders
  0B    /System/Volumes/Data/private/var/containers
  0B    /System/Volumes/Data/private/var/select
  0B    /System/Volumes/Data/private/var/netboot
 36K    /System/Volumes/Data/private/var/run
 36M    /System/Volumes/Data/private/var/protected
  0B    /System/Volumes/Data/private/var/rpc
  0B    /System/Volumes/Data/private/var/tmp
  0B    /System/Volumes/Data/private/var/backups
  0B    /System/Volumes/Data/private/var/agentx
  0B    /System/Volumes/Data/private/var/rwho

Now in my case I know that /System/Volumes/Data/private/var/db is the problem.

Reapplying the same method on that directory and digging deeper finally led me to /System/Volumes/Data/private/var/db/powerlog/Library/BatteryLife/Quarantine which was using practically the whole disk space. Deleting it solved the problem (for now).

Note: These are invented memory sizes.